Doesn't look like ash borer tunnels to me. From what I have seen and read, EAB seem to bore just single tunnels zig-zagging under the the bark rather than the central tunnel that was done by the adult which laid eggs along the sides of the tunnel. You can see where the adult bored in and then tunneled in both directions. The side tunnels were done by the larvae. At the end of the side tunnels, the larvae pupate and then bore their way out through the bark.
This is what I found for images of EAB tunnels. Looking at the life cycle, the EAB adult doesn't bore through the bark, It lays their eggs on the bark and the larva bores its way in and starts tunneling beneath the bark in a random pattern. You will see images like yours on websites identified as EAB but most are on tree service websites and such, not posted by entomologists.
There are several bark beetles that tunnel like your picture. Many, if not most, attack the tree after it has died or has been cut down.
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.
